490 THE PDP-10 FAMILY

Figure 1. Timeline of DECsystem-l0 evolution.

operational: a PDP-1 at Bolt, Beranek, and Newman (BBN) which used a high-speed drum that could swap a 4 Kword core image in one 34 ms revolution; an IBM 7090 system at MIT called CTSS, which provided each of 32 users a 32 Kword environment; and an AN/FSQ-32V at SDC, which could serve 40 simultaneous users.

The Bell Laboratory's IBM 7094 Operating System was a model operating system for batch users. Burroughs had implemented a multiprogrammed system on the B5000. Dartmouth was considering the design of a single language, timesharing system which subsequently became BASIC. The MIT Multics system, the Berkeley SDS 940, the Stanford PDP-1 based timeshared